A fuel cell such as a polymer electrolyte fuel cell is a device configured to generate electric power and heat at the same time by causing a fuel gas containing hydrogen and an oxidizing gas containing oxygen such as air to electrochemically react with each other at a gas diffusion layer that includes a catalyst layer of, for example, platinum.
Generally speaking, the structure of a polymer electrolyte fuel cell is such that an electrode layer and a gas diffusion layer are stacked in said order at both sides of a polymer electrolyte membrane. Types of the gas diffusion layer include one in which carbon fibers are used as a base material of the gas diffusion layer and one in which carbon fibers are not used as a base material of the gas diffusion layer. Patent Literatures 1 and 2 both disclose a gas diffusion layer, in which carbon fibers are not used as a base material of the gas diffusion layer.
Patent Literature 1 discloses a sheet-like electrode fabrication method where a rod-like preform that is formed of carbon fine powder, a fluorine-containing polymer resin, and a liquid lubricant is rolled out.
Patent Literature 2 discloses a gas diffusion layer for use in a fuel cell, which is formed from a porous member whose main components are electrically conductive particles such as acetylene black or graphite and a polymer resin such as PTFE.